| Graphite and It's Effects on the Human Body | | | | into the air. Also, because the vacuum hose |
| and Toolroom Equipment | | | | is often cumbersome to manipulate, operators |
| | | | fail to properly align the hose to capture |
| The health and welfare of toolmakers that use | | | | the most dust. |
| graphite to make electrodes for use in the | | | | |
| EDM department should be a high priority for | | | | Many shops use a centralized vacuum system |
| management. In addition to the health issues | | | | designed for the removal of fine dust |
| for the workers, the very expensive | | | | particles, such as graphite. It is important |
| machinery, such as the EDM machines and | | | | to have enough air velocity in the vacuum |
| milling machines, must be protected from the | | | | system to be effective. It is recommended to |
| damaging effects of graphite dust. | | | | have an air velocity of 500 ft. per minute |
| | | | and the air in the lines should travel at a |
| Anyone who has worked with graphite in the | | | | rate of 2,000 ft. per minute in order to |
| manufacturing of EDM electrodes is keenly | | | | prevent the dust from settling inside the |
| aware of the need for proper dust removal | | | | duct work. |
| during the machining process. Many | | | | |
| ill-equipped shops have very little equipment | | | | With a centralized system it is much easier |
| to handle the dust generated during milling | | | | to efficiently manage the dust from the |
| and grinding operations. | | | | various machine tools because the system is |
| | | | more efficient and the hoses can be |
| Safety | | | | strategically placed. Special wheel guards |
| | | | are available for surface grinders that act |
| The MSDS (material safety data sheet) for the | | | | as a turbo to remove the dust into the vacuum |
| synthetic graphite used in EDM show that | | | | system. |
| there are no carcinogenic properties | | | | |
| associated with graphite. It is a chemically | | | | Newer milling machines which are more or less |
| inert material and contains no volatile | | | | dedicated to electrode machining are equipped |
| components. It is also used for medical | | | | with extremely effective dust removal |
| purposes, such as implants and heart valves | | | | systems. The sealed chamber around the work |
| in the human body. | | | | area enables the vacuum to capture a high |
| | | | percentage of the dust. This development has |
| This is not to say that graphite is totally | | | | dramatically reduced the amount of graphite |
| harmless though. It can be very irritating to | | | | dust in the shop environment. |
| the skin, eyes, and nasal passages. It can | | | | |
| cause stinging, redness and watering of the | | | | An additional method of dust removal is the |
| eyes, and itching of the skin. This can be a | | | | use of a curtain of coolant surrounding the |
| very annoying experience when a toolmaker is | | | | milling cutter. This prevents the dust from |
| expected to produce a close-tolerance | | | | ever escaping and is very efficient. This |
| electrode with a fine finish. | | | | feature is available on some milling machines |
| | | | as well as an accessory that is easily |
| Controlling the Dust | | | | installed. |
| | | | |
| The simple but very ineffective solution is | | | | A Clean Shop Environment |
| to wear particle masks. Experience shows that | | | | |
| this stop-gap measure is a failure. The mask | | | | Graphite dust is highly conductive and has |
| soon is clogged with the fine dust and the | | | | been responsible for the damage of many |
| operator is left breathing a disgusting blend | | | | expensive tools and machines. Glass scales |
| of bad-breath and graphite dust! | | | | can give false measurements due to the |
| | | | settling of dust. Electronic equipment can be |
| Portable vacuums are the next best solution, | | | | short-circuited by the dust as well. The |
| but this also has many drawbacks. Often the | | | | grimy nature of graphite makes it especially |
| filter in the portable shop vacuum is not | | | | annoying if it accumulates on work-benches |
| fine enough to trap the microscopic sized | | | | and desks. |
| particles, and they are simply blown back | | | | |